My brother used to make azalea cuttings. He placed the cuttings in sand, in a clear covered container, outside in a semi shade location that never got full sun. I think that he always got at least 50% to root.
Be sure and have a node near the end that is placed in the medium. Also, use clean sand, or a sterile soilless medium or mix you own with peat, perlite, and vermiculite type of ingredients. Don't let the cuttings get too warm and don't expose them to too much light.
I have found that it is particularly easy to get cuttings to root in early spring. They root very quickly, sometimes without the leaves even whithering. I've done cuttings of butterfly bush then and didn't even use root hormone. Just make the cutting, strip or cut off all but small leaves, put in you soil, and stand back. Mid to late fall is also a great time to start cuttings. You don't even need to check on those until the following spring.
One last comment. My spice bush, and many other shrubs make small offshoots from the ground. Those can often be detached with some or most of their roots intact. They will grow and mature much more quickly than is the case with a stem cutting. I've propagated many of my plants, including blueberries, breath of spring, spice bush, and a few others that way. Won't give you a mass of plants, but if you just want an occasional addition then separating a rooted stem from the parent is a good method.